Task status/refresh
If a task status doesn’t appear to have updated, switch your view between grid view and status view, this often resolves it or if in Grid view, click menu, show current and the table will refresh. Note if a task is completed in the Task details screen the Case details screen will not refresh whereas if a task is completed when in the Case details screen (Tasks Tab) the table will refresh automatically.
CX Task & Case Overview
https://ondomain.sharepoint.com/sites/OS-Cxproject/SitePages/Cx-cases-and-tasks-overviews.aspx